1. Field of the Invention
The present invention relates to the art of electrical connectors, and particularly to a printed circuit board for a straddle mount electrical connector and a method for pasting the printed circuit board.
2. Description of the Related Art
Printed circuit boards are often used in the electronic field to receive electronic components, for example electrical connectors, thereon to cooperatively perform certain specified functions. One kind of electrical connector, so-called straddle mount electrical connector, is mounted to the printed circuit board with electrical contacts thereof electrically contacting with conductive pads on two opposite side surfaces of the printed circuit board.
When the conductive pads on a same side surface of the printed circuit board are arranged in two or more rows and a center line of one conductive pad in each row crosses or extends through a corresponding conductive pad in another row along a direction in which the straddle mount electrical connector is mounted to the printed circuit board, some of the electrical contacts of the straddle mount electrical connector would pass through the rows of conductive pads proximal to a front end of the printed circuit board to reach the conductive pads distal from the front end of the printed circuit board. Nevertheless, solder pastes are sometimes applied without reflowing over the conductive pads before the straddle mount electrical connector is applied to the printed circuit board, so the electrical contacts passing through proximal conductive pads often smear or plough most volumes of the xe2x80x9cwetxe2x80x9d solder pastes on these conductive pads, thereby causing shorting of the electrical contacts and reducing the reliability of the electrical connection between the conductive pads of the printed circuit board and the electrical contacts of the straddle mount electrical connector.
Therefore, an improved printed circuit board for a straddle mount electrical connector and a method for pasting the same are desired to resolve the above-mentioned problems.
A major object of the present invention is to provide a printed circuit board for a straddle mount electrical connector and a method for pasting the printed circuit board, which ensure an electrical connection between the printed circuit board and the straddle mount electrical connector.
A printed circuit board for a straddle mount electrical connector in accordance with the present invention comprises a first side surface and a second side surface opposite to the first side surface. Each side surface comprises a front and a rear rows of conductive pads and the conductive pads in the front row are staggered with respect to the conductive pads in the rear row. A plurality of solder pastes are applied to the conductive pads of the printed circuit board through a solder stencil having a plurality of openings. Each solder paste applied to the conductive pad in the front row is narrow and extends beyond the length of the conductive pad. The straddle mount electrical connector comprises an insulative housing and a pair of contact modules received in the insulative housing. Each contact module comprises a plurality of staggered signal and grounding contacts reaching corresponding conductive pads in the rear and the front rows of one of the first and the second side surfaces of the printed circuit board, respectively. The signal contacts, in reaching the conductive pads in the rear row, extend at least beside center lines of the solder pastes applied to the conductive pads in the front row, thereby reducing smearing or plowing volumes of these solder pastes by the signal contacts. After reflowing, the straddle mount electrical connector is reliably secured to the printed circuit board.
Other objects, advantages and novel features of the invention will become more apparent from the following detailed description of the present embodiment when taken in conjunction with the accompanying drawings.